A few thoughts: The watch would be the first thing to go. I’ll admit, I don’t understand all the features, but most of those are a lot more useful in town than when backpacking. It sounds like a training device, and when you are hiking, you aren’t training — you are doing. In some cases, it is nice to know your heart rate (to make sure it isn’t that high) but you can learn to take your own pulse (without a watch) or simply slow down, take deep breaths and go when you heart isn’t beating like crazy.
The Garmin Mini is the other end of the spectrum. It is easy to say you don’t need it, but it really depends on your particular situation. I know people with health issues and without it they would do different trips. Or their loved ones would be more nervous. I don’t use one, but I can definitely see the value.
GPS (on a phone or as a stand-alone device) is handy, but not essential in my book. It just makes things quicker. Map and compass (as well as good navigation skills and sensible choices) can work just as well, but they take longer. The Garmin also serves as a fallback if you really screw up. I tend to use GPS a lot more in the early season, when there is a lot of snow. But it really hasn’t changed my hiking — I just spend less time navigating. Unless you are doing a lot of tricky off-trail navigation, I would get by with map and compass.
The camera is the tricky one. I use the camera as a travelog of sorts. I eventually put the pictures on the web (on a Flickr account) and it allows me to catalog every hike. I really don’t need to do that for backpacking, as there are far fewer of those for me, and making notes about them would be much easier.
Once in a while I’ll take a really good picture, but I’m not a great photographer. I find it better to just explain that “the pictures don’t do it justice” then spending a lot of time getting the best shot. But that’s me. Photography is an art. There are lots of great photographers out there, and it more than just their technical prowess; it is their artistic expression. If that is you, then do your thing. But if you are just trying to show your friends what it is like, you are probably better off leaving it at home. Either they get it, or they don’t. Of course if you are taking pictures of your friends, that is, in some sense, priceless. There is a reason folks have photo albums consisting mostly of pictures of kids and grandkids.
But it doesn’t have to be one or the other. You might take it for a trip, then leave it at home the next time. My brother and his daughter hiked the Muir trail, and he left the camera at home. He is a much better photographer than me (his slide shows back in the day were stunning) but it isn’t like the area hasn’t been photographed before. It is liberating to not have a camera.
Or ignore it. As it turns out, yesterday was one of the best wildlife days in years, even though it was just a day hike. My wife and I saw pikas, marmots, bears and mountain goats all within minutes of each other. I took several pictures, but after a while, just ignored my camera. I kind of wish I had a better picture of that baby goat that was within about ten feet of me, but I didn’t want to spook the mom and besides, just enjoying the moment was nicer. There were plenty of other hikers, and plenty of other people taking pictures, many with lots better cameras (SLRs with a nice zoom lenses). I just don’t see how my pictures can compete.
Which leads me to my other story. While on a trip to Denali, the bus ran across its share of wildlife. We also woke up and saw the Northern Lights. But again, there were others with much better cameras taking pictures. I didn’t bother, but simply asked for the email address of the guy with the nicest camera. I referenced his pictures along with the ones that I took (when I was hiking solo). That’s cheating in a sense (I could still show up to my friends, without doing the work) but not that different than what my brother did. He (and his daughter) couldn’t show pictures from their trip (like I did) but they could point to the web if there is any question as to the beauty or type of terrain for their trip.
One last thing about the camera: While I often hike with my wife, I take plenty of trips without her. She really likes looking at my pictures, so there is that.